Created in the Anandtech forums, it was a member who posted useless crap to increase his post count. Hence, the term eventually branched out in to other forums and became a popular term among forum goers. Lifers are usually a harmless bunch, not as vicious as trolls. All they care about is the postcount..

short for "nephews", this word is commonly used to describe your close friends or relatives in the hood. This word is similar to the word "homies", but is used in more serious situations. Not to mention this word can also be used in place of "swear to god"

"Nefs I ain wit that breezy takin my bank rolls"
or
"I gat nefs in this hood that will knuck if you talk shit"